气溶胶光学吸湿增长特性测量方法研究进展

吸湿性气溶胶会吸收环境空气中的水分,其粒径会随相对湿度的增加而发生变化,从而导致气溶胶的光学特性(如消光、散射、吸收系数与单次散射反照率等)发生显著的变化。气溶胶光学吸湿增长因子(湿状态与干状态下光学参数的比值)是衡量气溶胶光学吸湿增长能力的特征参数,是计算大气能见度和气溶胶辐射强迫的关键输入量,它的准确测量对于气溶胶环境和气候效应的评估具有重要意义。光学吸湿增长测量系统主要包括湿度调节系统和光学测量装置,通过湿度调节系统改变样品的相对湿度,再结合光学测量装置实时测量光学参数的变化,从而实现光学吸湿特性的在线测量。鉴于气溶胶吸湿性研究的重要意义,重点分析对比了现有的光学吸湿增长测量方法及应用,并对下一步气溶胶光学吸湿增长特性测量技术和研究方向做了展望。

Research progress of methods of aerosol optical hygroscopic properties measurement

Hygroscopic aerosols can take up water in ambient air, and their particle size will change with the increaseof relative humidity, leading to dramatic changes in optical properties (such as extinction, scattering and absorptioncoefficients, and single scattering albedo, etc.). The hygroscopic growth factors of aerosol optical properties (theratio of optical parameters in wet state to dry state) are characteristic parameters representing the growth capacities ofaerosols optical hygroscopicity, and also key parameters in assessing the effects of aerosols on atmospheric visibilityand radiative forcing. Thus, accurate measurment of optical hygroscopic growth factors is of great significance forthe evaluation of aerosol environment and climate effects. The optical hygroscopic growth measurement systemconsists of an optical measurement device and a humidity control system. The humidity adjustment system is used tochange and control the relative humidity of samples, and the optical measurement device measures the correspondingchanges of optical parameters in real time to achieve the on-line measurement of optical hygroscopic properties. Inview of the significance of aerosol hygroscopicity research, the existing optical hygroscopic measurement methodsand their applications are analyzed and compared comprehensively, and the research directions of measurementtechniques and experimental works on aerosol hygroscopicity in the future are prospected.